Clasp envelopes are made with sturdy manila material to ensure more protection to the enclosed materials and can be used for home or business use. There is a small, bendable metal clasp that holds the sealed part of the envelope in place. Tape can be put over the clasp to prevent the clasp from catching onto other materials.
Put your material into the envelope and address the front side.
Wet the gummed flap.
Squeeze the clasp by bending the metal part together and pushing it through the hole on the flap end.
Open the metal clasp and flatten it. Press the flap of the envelope so the envelope stays securely closed.
Take a piece of packing tape as long as the envelope is wide and tape the sealed flap closed. This will prevent the metal clasp from catching onto another piece of mail and opening.
Bring the envelope to the post office, weigh it, pay for the postage and drop it in the outgoing-mail slot.
Your envelope must meet standard United States Postal Service guidelines for shape and weight or it could get lost in the mail. Envelopes must be rectangular and measure at least 5 inches long, 3.5 inches high and seven-thousandths of an inch thick. Customized envelopes can be no longer than 11.5 inches, a 6.125 inches wide and a quarter of an inch thick.